#include <iostream>
using namespace std;

int max(int a, int b, int c)
{
	int m;
	if(a > b)
		m = a;
	else
		m = b;
	if(c > m)
		m = c;
	return m;
}

int main()
{
	int a, b, c;
	cin >> a >> b >> c;
	float m = max(a, b, c) * 1.0 / (max(a+b,b,c) * max(a,b,b+c));
	printf("%.3f\n", m);
//	cout << max(a+b,b,c) << endl;
//	cout << max(a,b,b+c) << endl;
	return 0;
}
